Air speed-indicator for use on aeroplanes and the like.



If. II: CIIFLQ Y AIR SPEED INDICATOR .FOR use 0N AEROPLANES'AND'TH'E L'IIIE.

APPLICATION FILED SEPT. 21. IBI?. l'

1,267,633. PIII'IIIIIIIIII May28,1913.

INVENTOFI. 7W

the motion of the aircraft throughV ,the air reaches a certain deined' and pre-arranged rzannnnrc noLLocooMBncLIrm. or BARNES, Lennon, ENGLAND."l

. /sPEED-rNnIcAror. non

To all 'whom it may concern.'

Be it known that I, FREDERIC HomocooMBn Curr, a'subject of the King of Great Britain and Ireland, residin at 95 Castlenau, Barnes, in the county of ndon,` England, have invented new and useful Improve'ments in' and Relating -to.iii1',Speedv ,Indicatorsifor Use onI Aeroplanes and the like, of which the .following is a speciical tion.

.This invention `relates to indicators for denoting 1the speed at which aeroplanes and thel like are traveling, and it consists of an instrument operated by a' pressure and static pipe for producing an audible signal when speedf'the object being tov convey to the pilot or other occupant ofthe machine that the speed ofthe craft has dropped to a dangerously low rate. i

. According to the present invention, the movement of a diaphragm or its equivalent operated by means of the usual pressure and suction or static pipes', as is employed in' speed indicators of thetype in' which the mechanism is operated by the pressure of air due to the relative movement of thel machine and the air, is employed to -complete an' electric circuit and produce by 'an electrical buzzer or other suitable sound-producing device an audible signal when the speed of the machine has dropped below Ia predetermined rate. n

The pressurev and suction or static pipes are. preferably located in the slip stream of the propeller of-the Vmachine so that the laudible. signal will be produced' at different speeds atwhich the machine is moving ac cording to whether it is gliding, z'. e., not

` being driven by the propeller, or is being vided that it will suffice the audible signal is given at one speed only.

propelled, but this is not'obligatory pro- In the accompanying to this invention Figure 1 is a diagrammatic view showing the several parts,

Fig. 2 is a view in plan from theunderside of the Contact maker, and

` Fig. 3 is avview in section of said device. Throughout* the views similary parts are marked with like letters of reference.k

In a case a .is mountedA a exible diaphragmV b so as to formtwoi chambers, `a

` terminal 1.

drawing which shows an instrument constructed according contact points el and m1 and thus regulate Speci'atm OfLefterS'-afet- Patented. Mayas, 191s. Appli-cation filed September 21,1917. Serial'No. 192,513.'l i i pressure chamber 'c and a suction or as it is more generally designated' static-chamber d, into which are led the pressii'rejand suction or static pipes c1 and d?. On the bottom teriorterminalf. The diaphragm b .carries a ipi'n It or the likel which on deliection by reason of the pressure in the chamber-'c con# ytacts the spring finger e and imparts an outward movementtQ it. Mounted ontle bottom of and within the case a is anotherflat spring finger .m which is arranged transversely to `and above the spring finger (Z. This spring is alsoI insulated from the case a in any suitable mannerand has an exterior each, carries. a platinum orV other suitable contact poi'n't e1 ari/d m1. These points are normally in contactso that the electric circuit .through the terminals f and f1 is closed and the buzzer w, which is in said circuit together withJ 'the battery o, sounds, but' when the machine is flying and -attains the into contactA again with the contactv point m1v carried by the spring mV by reason vof AThese two nge'rse and 1n)v the movement of the diaphragm-b due to the reduced air pressure on it which thus completes thegelectric circuit througlnthe teiiirnals f and f1 "and sounds the buzzer,l The l electric buzzer is preferably independentsof position to the pilot.-

`the instrument and is fixed in suitable juzlftaV To adjust the position ofthe contact point f 'm1 carried by the finger m in relatio'r to the `.cbntact point el carried by the finger e in order to vary the normal position of the y tweenithecontact points c1 and m1, On the screw n is mounted a pinion 0 which gears with a spur wheel 1" mounted on a spindle s' carried in suitable bearings on thecaee af By rotating this spindle by means of a suitable hey or the like the necessary motion can be impartedto the screw f/t to adinst the relative positions ci the contact points el and mb v in which. the pressure of air onlyE due to the relative movement of the machine and the CIK air, is employed, in 7which case a single diaphragmniay be employed to operate both the visual readingand the audible indicators. ln order that the audible signal shall not be given when the aircraft is commencing or endingl a `liight when its speed is naturally low a switch e may be introduced into the electric circuit.

lVhat l claim as my invention and desireV to secure by Letters latent ir:-

l. ein 4audible speed indicator' forl aeroplanes and the like comprising' a case di- TJided by means of a flexible diaphragm into two chambers one a pressure chamber and the other a so-called static chamber, a pressure pipe leading into the pressure chamber7 a suction pipe leading inte the static chamber, a tlat spring linger mounted in the static chamber and insulated from the case,

Y a contact point carried by said spring in ger, a terminal connected to said linger, a second spring finger similarly mounted in said case, a contact point carried by said spring linger and adapted to engage the Contact point carried by the other spring nger, a terminal connected to said second 'spring fingerg a pin carried by the -dia-- phragm and adapted to contact the lirst spring tingen ineansi'or adjusting' the posi tion of one of the contact points carried by one of the spring fingers relative to that car-- ried by the other spring ringer, an .electric buzzer or the lihe a battery or other source or electric energy and an electric lead connecting said contact. inalrer7 buzzer and battery. y

i 2. in audible speed indicator for aeron planes and the like, comprisingI a case diyided by means of a ezrible diaphragm into two chambers, one avpressure chamber and the other a sc-called static chamber, a pressure pipe leadinginto the pressure chamber7 a suction .pipe leading' into the static cham ber, a dat spring linger mounted in the static chamber and insulated from the casa' a terminal connected. to said spring finger, a second spring linger similarly mounted and haring a similar termina, a-

or projection'earried by the diaphragm and adapted to contact the first spring finger, electric contact points carried by the two spring lingers and opposed to' one another, means 'for adjusting the position of .one of these contact points relative to the other, an elec tric buzzer or the like-and a battery or other source of electric energy both of 7which are coupled up in circuit with the instrument through the terminals connected to the 'spring fingers, and means for adjusting the speed at whichthe instrument will produce the audible signal.

inaudible speed indicator for aerow planes and the like, comprising a case diyided by means oi a le'ible diaphragm into two chambers, one a pressure chamber and.

the other a socalled static chamber, va pres-A sure pipe leadinginto the/pressure chamber7 a suction pipe leading into the static charnber, a hat spring finger mounted in the static chamber and insulated'from the case7 a terminal connected to said spring fingen a second Aspring nger similarly mounted and having a similar terminal, a pin or proL jection carried by the diaphragm and adapted to Contact the rst spring linger, electric contactpoints carried by the two spring hngers and-opposed to oneA ai'iotl'ier.7 means for adjustingl the position of one or these contact points relative to the othern an electric buzzer or the like and a battery or other source or electric energy both of which are coupled up incircuit With the instrument through the terminals connected tothe Sil spring ngers, and means for indicating atA` what speed-the instrument will produce the audible signal.

l. fin audible speed indicator for aeroplanes `and the lilre,-comprising a case dil vided by means of al denible diaphragm intotwo chambers one a pressure chamber and the other a vso-called static chamber., a

vpressure pipe leading 'from a'position in the slip stream of the propeller of the aeroplane tothe pressure chamberI` a. suction pipe leading from a position in the slip stream or the propeller of the aeroplane to the static chamber, a dat spring` nger mounted N inthe static chamber and insulated from the case, a. terminal connected to said spring finger, a second spring nger similarly mounted and having a. similar terminal, a boss or projection carried by the diaphragm and adapted to Contact the first spring linger, electric contact points carried Aby the tiro spring lingers and opposed to one an otherj means i'or adjusting the position oi one of these contact points relative to the other and an electric buzzer or the. like and a battery or other source orn electric energy both of which are coupledup in circuit to the spring lingers.

o. in audible' speed indicator for aeroplenes and the like, comprising a case di: h

vided by means of a flexible diaphragm into two chambers one a pressure chamber and the other a so-called static chamber, a pres- -electric contact points carried by the twov spring lingers and opposed to one another,

means for adjusting the position 'of one of these contact points relative to the other, means for adjusting the speed at which the instrument will-produce the audible signal, means for indicating at what speed the instrument is set to produce the audible signal, and an electric buzzer or the like, a' switch and abattery or other source of electric energy said contact maker buzzer switch and c battery being coupled up in one circuit.

6. The combination with a visual reading speed indicator of the type specified 4of a speed indicator of the audible type, comprisinga case such as a divided by a diaphragm Z7 into a chamber c and a chamber d, a pipe c1 leading into the chamber c, a pipe Z1 leading into the chamber d, a spring finger e' insulatedly mounted in the chamber (Z1, an

electric Contact point el carried, by said linger, an lexteriorterminal f in connection with-'said linger, means of contact between the diaphragm and the nger e, a spring finger m vinsulatedly mounted within the chamber d, an electric contact point m1 carried by said Enger, an exterior terminal f1 in connection with said Enger m, a screw n for 4adjusting the position of the Contact point m1 carried' by the nger e, and an electric buzzer 'w orthe like placed in circuit with the contact points e1 and 'm1 through` the 'terminals f and f1 and an electric battery o.

7. The combination with a visual reading speed indicator ci the type speciiied, the combination of a speed indicator of the audible type which comprises a case such as a divided by a diaphragm b into a chamber c and a chamber d, a pipe c1 leading into the -chamber c, a pipe (Z1 leading into the chamber ai, a spring finger e insulatedly mounted in the chamber d, an electric contact point e1 carried by said linger, means of Contact -between thediaphragmy b Aand the finger @,'a

spring finger m insulatedly mounted within Vthe chamber an electric contact point m1 Vcarried by Said Enger, an exterior terminal ,f1 iu connection with said nger m, a screw fa for adjusting the position of the contact point m1 carried by the linger m in relation to the contact point el carried by the nger e, a spindle s, mounted in suitable bearings adjacent to the screw n, gearing between the spindles, and the screwI n, a dial 'over which said hand or index moves, means'fo'r rotating the spindle s, and a battery o a switch .e and an electric buzzer 'w or the like all placed'in circuit with the contactpoints el and m1 of 'the contact maker., y

8. In a'speed indicator of the audible type for aeroplanes and the like, the combination of a case such as a divided by la diaphragm'` b into'a chamber c and a chamber d, a pipe 01 leading from a position in the slip stream of'thepropeller oftheaeroplaneinto the chamber c, a pipe Z1 leading from a position in the slip stream of the propellervof the aeroplane into the chamber d, a spring finger. e`insulatedly mounted in the chamber d, an

electric contact point- 'e1 carried by said linger, an'exterior terminal f in connection with said finger, means of contact between the diaphragm b and the linger e, a spring nger m insulatedly mounted within the chamber al, an electric contact.` point m1 carried bysaid finger, anv exterior terminal f1 in connection with said inger m, a battery 0, Y and an electric buzzer 10,'said contactmaker,

buzzer and battery being connected up in one circuit. 9. In a speed indicator of the audible type for aeroplanes and the like, ,the combination of a case sich as a divided by adiaphragm t into a chamber aand achamber d, a pipe c1 leading from a position intheslip stream of the propeller ofthe aero laneinto the chamber e, a pipe Z1 leading rom a position in the slip stream of Lthe propeller of the aeroplaney into the chamber d, a spring finger einsulatedly mounted in a chamber d, an

electric Contact point e1 carried by said linger, an exterior terminal f 1n connection with said finger, means of contact between the diaphragm?)L and theinger e, a spring linger mv insulatedly mounted within thej y chamber d, an electric contact pointJ m1 carried by said finger, an exterior terminal f1 .in connection with said finger m, a screw n for adjusting the position of the contact point m1 carried by the linger e, a battery lv, a switch' a and an electric buzzer fw, said contact maker, buzzer, battery and switch being connected up in one circuit.

10. ln a speed indicator of the audible type for aeroplanes and the like, the combination of a case such as a divided by a diaphragm t into a chamber c and a chamber d, a pipe cI leading from a position in the slip stream of the propeller of the' ina chine into lthe chamber c, a pipe Z1 leading lfrom a position in-the slip stream of the propeller of the machine into the chamber d', a spring nger e insulatedly mounted in the chamber d, an exterior terminal in connection with said finger, means of commet @oe *tween the diaphragm Z and the 4funge? e, el Spng nge m nsulatedly mounted Within the ohambe d, en electric Contact point m1 eafred by sa. finger, an exterior terminal f1 in connection with said Enger m, a screw' n o adjusting the position of the eoptaet point mi oaed by the Enger 'm7 a, spmdle s mounecin suitable bearings adjacent toV he screw gealng between the spinde s and the seew n, e, han@ or mde Enger eere by @he spindle s, e dial a; over which seid hand or index moves`means for rotating the spindle s? a batery'o., a switch e m a buzzer fw and en eeefalead Connecting said Contact makerE buzzer, switch and oattely in one circuit.

Dame.

FREDERIC HLLOGOOMBE CLFT.-

Wnesses:

Hmm? Bemes'oois, CHARLES Fece.

n estmony whereof I have signed my' 

